#include "HsVersions.h"
-import SimplMonad
+import SimplMonad
import IdInfo
import CoreSyn
import Rules
import BasicTypes
import DynFlags
import Util
+import MonadUtils
import Outputable
import Data.List
\begin{code}
-substId :: SimplEnv -> Id -> SimplSR
+substId :: SimplEnv -> InId -> SimplSR
+-- Returns DoneEx only on a non-Var expression
substId (SimplEnv { seInScope = in_scope, seIdSubst = ids }) v
| not (isLocalId v)
= DoneId v
| otherwise -- A local Id
= case lookupVarEnv ids v of
- Just (DoneId v) -> DoneId (refine in_scope v)
- Just res -> res
- Nothing -> DoneId (refine in_scope v)
+ Nothing -> DoneId (refine in_scope v)
+ Just (DoneId v) -> DoneId (refine in_scope v)
+ Just (DoneEx (Var v))
+ | isLocalId v -> DoneId (refine in_scope v)
+ | otherwise -> DoneId v
+ Just res -> res -- DoneEx non-var, or ContEx
where
-- Get the most up-to-date thing from the in-scope set
Just v' -> v'
Nothing -> WARN( True, ppr v ) v -- This is an error!
-lookupRecBndr :: SimplEnv -> Id -> Id
+lookupRecBndr :: SimplEnv -> InId -> OutId
-- Look up an Id which has been put into the envt by simplRecBndrs,
-- but where we have not yet done its RHS
lookupRecBndr (SimplEnv { seInScope = in_scope, seIdSubst = ids }) v
\begin{code}
simplBinders, simplLamBndrs
:: SimplEnv -> [InBndr] -> SimplM (SimplEnv, [OutBndr])
-simplBinders env bndrs = mapAccumLSmpl simplBinder env bndrs
-simplLamBndrs env bndrs = mapAccumLSmpl simplLamBndr env bndrs
+simplBinders env bndrs = mapAccumLM simplBinder env bndrs
+simplLamBndrs env bndrs = mapAccumLM simplLamBndr env bndrs
-------------
simplBinder :: SimplEnv -> InBndr -> SimplM (SimplEnv, OutBndr)
-------------
simplLamBndr :: SimplEnv -> Var -> SimplM (SimplEnv, Var)
-- Used for lambda binders. These sometimes have unfoldings added by
--- the worker/wrapper pass that must be preserved, becuase they can't
+-- the worker/wrapper pass that must be preserved, because they can't
-- be reconstructed from context. For example:
-- f x = case x of (a,b) -> fw a b x
-- fw a b x{=(a,b)} = ...
-- The "{=(a,b)}" is an unfolding we can't reconstruct otherwise.
simplLamBndr env bndr
- | not (isId bndr && hasSomeUnfolding old_unf) = simplBinder env bndr -- Normal case
- | otherwise = seqId id2 `seq` return (env', id2)
+ | isId bndr && hasSomeUnfolding old_unf = seqId id2 `seq` return (env2, id2) -- Special case
+ | otherwise = simplBinder env bndr -- Normal case
where
old_unf = idUnfolding bndr
- (env', id1) = substIdBndr env bndr
- id2 = id1 `setIdUnfolding` substUnfolding env old_unf
+ (env1, id1) = substIdBndr env bndr
+ id2 = id1 `setIdUnfolding` substUnfolding env old_unf
+ env2 = modifyInScope env1 id1 id2
---------------
simplNonRecBndr :: SimplEnv -> InBndr -> SimplM (SimplEnv, OutBndr)
take advantage of the 'state hack' on the result of
(f y) :: State# -> (State#, Int) to expand the arity one more.
-There is a disadvantage though. Making the arity visible in the RHA
+There is a disadvantage though. Making the arity visible in the RHS
allows us to eta-reduce
f = \x -> f x
to
where
subst = mkCoreSubst env
old_rules = idSpecialisation in_id
- new_rules = CoreSubst.substSpec subst old_rules
+ new_rules = CoreSubst.substSpec subst out_id old_rules
final_id = out_id `setIdSpecialisation` new_rules
------------------